Which statement accurately describes tides?

Which statement accurately describes tides?

• A. The Sun's gravity is the sole cause of tides
• B. Tides arise from the Moon's gravity only
• C. Tides arise from the gravitational forces of the Moon and Sun; the Moon has the largest influence due to proximity
• D. Tides are caused by wind stress on the ocean surface

Answer: (C)

Tides come from gravity acting on Earth's oceans, but what matters is the difference in gravity across the planet—the tidal or gravitational gradient. The Moon is much closer to Earth, so its gravitational pull varies more across Earth, creating noticeable bulges on the side nearest the Moon and on the opposite side as well. The Sun is far away but enormously massive, so it also stretches the oceans, though its tidal effect is smaller on average than the Moon’s. Together, their gravitational forces produce tides; when their pulls align, tides reinforce each other and produce higher highs and lower lows, while when they are opposite, they partially cancel and tides are smaller. So tides arise from the combined gravitational forces of the Moon and the Sun, with the Moon having the larger influence because of its proximity. Wind can drive waves, but it isn’t what creates tides.

Tides come from gravity acting on Earth's oceans, but what matters is the difference in gravity across the planet—the tidal or gravitational gradient. The Moon is much closer to Earth, so its gravitational pull varies more across Earth, creating noticeable bulges on the side nearest the Moon and on the opposite side as well. The Sun is far away but enormously massive, so it also stretches the oceans, though its tidal effect is smaller on average than the Moon’s. Together, their gravitational forces produce tides; when their pulls align, tides reinforce each other and produce higher highs and lower lows, while when they are opposite, they partially cancel and tides are smaller. So tides arise from the combined gravitational forces of the Moon and the Sun, with the Moon having the larger influence because of its proximity. Wind can drive waves, but it isn’t what creates tides.